1. Field of the Invention
The instant invention relates to a flow control valve and more particularly to such a valve which is suitbale for controlling fluids at high pressures and flow rates.
2. Description of the Related Art
A typical prior art flow control valve includes a stem having a cone mounted on the lower end thereof which is movable toward and away from an orifice for regulating flow therethrough. The cone and orifice are received in a housing cavity which is in fluid communication with an inlet. The orifice is in fluid communication with an outlet. In operation, fluid enters the inlet and leaves the outlet at a reduced pressure and/or flow rate depending upon the relative positions of the cone (which is set by turning the stem) and the orifice.
Such prior art valves suffer from several disadvantages. Under extremely high flows and pressures, large axial forces are exerted on the stem making the same very difficult, if not impossible, to adjust when fluid is flowing through the valve. In addition, the turbulent nature of the flow between the cone and the orifice causes both wear on the valve parts and extremely loud noise. Such prior art valves are relatively imprecise in that the same orifice opening may not be obtained when the stem is rotated to different angular positions and thereafter returned to a previous angle position. In other words, a desired valve setting may not necessarily be repeatably obtained.